Explore beautiful new homes for sale in Coolidge, AZ, by Century Complete. Located in Pinal County, Coolidge was founded in 1925 when R.J. Jones established an 80-acre site during the construction of the Coolidge Dam on the nearby Gila River. Both the dam and the townsite were named for Calvin Coolidge, the 30^th President of the United States. The dam transformed the area's native sandy soil into rich farmland, and soon vast expanses of desert were plowed and acres of cotton were planted. This is when the area's status as the hub of the Arizona cotton industry was solidified—leading to the incorporation of Coolidge as a city in 1945.